The present invention relates generally to storage subsystems for tiered storage management and, more particularly, to storage I/O (input/output) methods based on tiered storage using the various storage devices such as SSD (Solid State Disk) and HDD (Hard Disk Drive).
Recently, IT (Information Technology) platform has been utilizing new storage devices such as flash which is a SSD. A SSD provides much higher storage I/O performance as compared to conventional storage media such as a HDD. This provides substantial motivation to use tiered storage management to improve the storage I/O performance and optimize the cost. Leveraging SSD and HDD can be used for storage tier management. A mixture of SSD and HDD provides not only more storage I/O performance but also enough capacity for the data. The data which is accessed much should be located on the SSD; in contrast, the data which is not accessed so much (which tends to be much data) should be located on the HDD.
The storage tier management will also require a tier management of storage networking (network quality management). For instance, 30% capacity of much accessed data on SSD and the rest on HDD policy needs 80% bandwidth for SSD I/O and 20% bandwidth for HDD. Network bandwidth should be allocated properly. Additionally, latency of SSD is faster than HDD (SSD is around 50 μs, HDD is around 1000 μs). Therefore, network latency for SSD I/O should be very much lower than that for HDD I/O.
Recently, various I/O configurations such as LAN, SAN (Storage Area Network), IPC (Inter Process Communication) are going to be consolidated. A single network path such as a network interface (port) and network switch gear has to manage various types of I/O configurations. A single network path has to manage and differentiate network qualities (bandwidth, latency, security, etc.) of each type of I/O. Current solution provides priority-based network controlling methods such as IEEE 802.1Qbb and IEEE 802.1Qaz. By using these technologies, an IT platform can prioritize several I/O traffic protocols such as LAN (Local Area Network), SAN, IPC, and the like. However, read/write I/O for SSD and read/write for HDD will be treated the same because all storage I/O will be consolidated as a single I/O path. There is no method to differentiate each tiered storage I/O from the others.